Before beginning construction or underground excavation, it is necessary to determine the location of underground obstructions that may be in the area of the intended construction or excavation. Various methods of locating such obstructions have been employed in the prior art. For example, electronic locaters may be employed that attempt to locate underground obstructions without actually penetrating the soil. However, these electronic locators are not always accurate, and a mechanical means of penetrating the soil and checking for obstructions is often desired. A common method in the prior art for locating underground obstructions is to force a rigid rod into the ground by hand to a desired depth. This requires substantial effort on the part of the operator, both in the insertion and removal of the rod, and can lead to injuries such as pulled muscles and back strains. An improved method of mechanically locating underground obstructions is therefore desired.